Core B will provide 3 primary functions to the Program Project. First, Core B will provide research specimens to the investigators and assist with identification, immunostaining and image analysis. Paraffin-embedded sections will be provided from original tumors or tissue microarrays and used to 1) confirm tissue histology using routine H&E;2) analyze apoptosis using ACINUS, proliferation using MIB-1 detection of Ki-67 or BrdU incorporation and androgen receptor using monoclonal antibodies by standard, descriptive immunohistochemistry and quantitative analysis using visual scoring and/or automated image analysis;and 3) identify and quantify steroid receptor co-regulators, androgen metabolism enzymes, androgen-regulated gene products (PSA, Nkx3.1, a-tubulin, translation elongation factor 1a, non-neuronal enolase, tomoregulin, thioredoxin reducatase 1, Mxi-1 and human kallikrein 2), general transcription factors, growth factors and their receptors and stem cell and angiogenesis biomarkers using immunohistochemistry and image analysis. Second, Core B will be responsible for storage, processing and sectioning of clinical (frozen, archival and TMAs) and prostate cancer xenograft (CWR22) research specimens. Core personnel will procure, process and store clinical specimens of castration-recurrent prostate cancer obtained from men with advanced prostate cancer who present with urinary retention due to local recurrence. Research specimens will be used to construct tissue microarrays or laser capture microdissected for biochemical measurements of tissue androgens. Lastly, Core B will provide expert biostatistical (Dr. Wilding) and genitourinary pathological service (Dr. Alexiev) to the Program Project. Drs. Mohler and Smith will co-direct the facility and supervise the activities of individuals who already possess high levels of expertise and currently perform these functions for the Program Project. Drs. Wilding and Alexiev will lead the efforts to integrate biostatistical and pathological expertise into Core B and the 3 projects. The high level of function of Core B is demonstrated best by Core B's publication of 8 methods papers. Core B continues to develop new methods for more accurate measurement of protein expression (4 publications) and remains a leader in the use of TMAs for CaP research (2 publications). Core B has performed services that have resulted in manuscripts published, in press and submitted for Project 1 (20), Project 2 (8) and Project 3 (8). Core B also facilitates interaction among the Projects;12 of 23 publications involved more than 1 Project.